Preoperative hemoglobin level and risk of new-onset atrial fibrillation and flutter after total joint arthroplasty: a retrospective analysis

This retrospective cohort study investigated whether low preoperative hemoglobin levels increase postoperative atrial fibrillation and flutter (POAF) risk following elective total joint arthroplasty. Using the TriNetX Analytics Network Platform, we analyzed patients aged ≥ 40 years undergoing primary knee or hip arthroplasty under general anesthesia between 2010 and 2024. Patients were categorized into low hemoglobin (8-12 g/dL) and control (> 12 g/dL) groups. After 1:1 propensity score matching yielded 22,996 pairs, Cox regression analysis revealed significantly higher six-month POAF incidence in the low hemoglobin group (1.4% vs. 0.97%; HR 1.39, 95% CI 1.17-1.65, p < 0.001). The low hemoglobin group also demonstrated increased all-cause mortality (1.0% vs. 0.47%; HR 2.10, p < 0.001) and ICU admissions (1.4% vs. 0.84%; HR 1.65, p < 0.001). Even mild hemoglobin reduction (10-12 g/dL) significantly elevated POAF risk (HR 1.35, p = 0.001). Temporal analysis showed peak POAF risk occurring 30-180 days postoperatively, with effects persisting up to three years. These findings establish low preoperative hemoglobin as an independent, clinically significant risk factor for POAF and adverse outcomes following orthopedic surgery, suggesting preoperative anemia correction may be a valuable intervention for improving postoperative outcomes.